Found this this morning doing a "crawl under and inspect because the weather is nice and I'm doing lawn maintenance today".

I suspect this just blew last night sometime, looks pretty fresh. Had a drive of about 30min after a night of watching monster truck jam carnage at Cowboys stadium. Probably suits me right for cheering when I saw parts break off trucks when they landed.

Could just be the seal but I have to admit to hearing a very slight whir at speed. But it is so slight that I question whether it is really there or not. Just noticed the last day or two.

So, I gotta fix it or have it fixed. I kinda don't feel like I want to be monkeying around with it on my own, though I have a second vehicle. But I'd hate to get stuck or screw it up. Never done a pinion seal or bearings. I'm kinda leaning....<gulp>..not gonna say it...but, you know where...

Truck has ~>63k. I did the diff fluid change at 58k (for the 60k service). Should I consider bearing replacement while in there or not? Guess that will depend on what is found when it is disassembled eh?

 

Dodge says to change the diff fluids every 15k. Check the yoke for any play, if none then I would change the fluid out again. Go with 75/140 and see it that helps. The diffs came with 75/90 in them, I believe Dodge put a bulletin out saying to go to the heavier 75/140. Believe it or not, different brand oils may behave differently within a given application. Some times you get a leak and other times a noise or vibration. The easiest thing to try first would be a fluid change.

Good luck.

 

Yep, the last change was at 48k and I bought the truck at 32k and 'was told' by the dealer the fluids all hand been changed. I use 75w90 Mobil 1 for my changes. I'm doing 100% on road, city & hwy right now between DFW metro and home in CC.

Will check for play. I know there is some movement in the front dshaft although I have never been able to pinpoint exactly where it is manifesting. The best I can tell it has been play at the tcase output shaft end. But I was told on the forums somewhere that a slight play was "normal" whether or not that was true, I really don't think so but just what I was told. I was secretly hoping a ujoint would grenade somewhere so I would know which one to replaced if it was in fact a ujoint. I make certain to keep that well-hidden zerk in the dshaft greased up.

Will look into the 140. One thing I do wonder about is the affect of the weather (hot or cold) has on the seals and rubber parts. A few days it is warm, the rest of the week it is frigid. Seems that is the cycle every week.

 

Shorts, pull the plug and see if there's any unusual metal on the magnet. If so, tow it in for the replacement, don't drive it.

Tim, if you find that bulletin would you post it here?

 

Pulled the plug and it really had nothing on the magnet but I park the truck on an incline so the fluid level doesn't rest level (away from plug). Any possibility that affects what sticks to the magnet?

I think I better go get some more diff fluid and pull the cover off. Not knowing because I won't pull the cover is dumb. Can I pull it into and out of the garage (level floor) or should I not move it at all?

So, go with 140 then? Spring & summer are around the corner.

 

Shorts,

Nah! The incline should not affect the ferrous material stuck to the magnet at all. If is sticks..it's stuck there. Good idea to pull the cover for a look and change to the Mobil 1 75w/140 is a good idea as well.

Also, pinion bearings tend to whir, rather than rumble, because the pinion is turning several times faster (depending on gear ratio) than the carrier. We recently had pinion bearings replaced in a company Dodge CTD that ran low on fluid from a seal that blew out over a the course of 750 miles. However, the picture you show looks a if this just occurred recently. I would change the fluid and proceed from there as I doubt that the pinion bearings were compromised.

 

The pinion seal should not set you back too much if you have it replaced by an independent repair shop.

 

Thanks Dr Dizzle. I'm out to grab 140 and I'll report back what the inside looks like.

 

It's a little drip. Nothing to get alarmed about. Don't need to change fluid or pull the diff cover since the fluid is new (10k mi is new especially since its just a DD and not towing 20k everywhere. I changed mine at 20k and again at 100k recently, fluid looked good still. )
Pinion seal is pretty easy unless AAM axles are different than every other one I've done. You pull the driveshaft and u joint. Then unbolt the pinion flange w a impact. Pop the flange off with a puller. Replace the seal and put it back together. Then top off with fluid.
It's an hour or 2 job with an impact wrench, the right socket and puller for the flange.
Don't sweat it. Even having a shop do it shouldn't be much over $100-150.
A buddy had one done when he was on the road last year. It blew out and needed done right away. Some little backwoods shop had him back on the road in about an hour and $100.

 

Grit dog, too late.

The fluid looks great, pretty clean in there. Looks good except...got some marks on the ring teeth that I need eyes to look at. Gonna get photos. And finish off the visual with a good light.

 

Have a look. I left them big so some detail can be seen. I'm fairly certain these grind marks/surface gouges weren't there at 58k. I definitely would have noticed and I would not have thought "Hm maybe I can bump the interval up since the fluid was in good condition and was the hardware".

Am I sitting on a grenade or what?









The marks on the ring can be felt with a fingernail and the bigger marks with the skin of the finger, feels rough. The pinion though has a chip off the corner that's completely obvious to eyes and feel. Also, I didn't find pieces or chunks of metal in the bottom of the diff.

I don't want to be hasty and jump the gun. But I also don't want to grenade and take out a lot more. I don't know what caused the chippage in the first place, that is a concern.

I did button up the diff and refill with 140 fluid, so I just stuff $60 in there

 

At that mileage your gears have hardly even gotten used to each other, and rear ends are pretty simple, once the gears are set up properly they aren't going to grenade unless you run it right dry of oil. I wouldn't worry about the marks on the gears at all.

Maybe the new axles are a little more sensitive, but my last truck (2000 Superduty dually-Dana 80) sprung a pinion leak that had me adding half a liter a day for almost two weeks before i fixed it just because we were swamped and it was easier to find ten minutes at a time than two hours. I pulled the pinion expecting to replace the bearings and was surprised to find them in perfect condition. It helps that the differential bearings are never subjected to any serious heat as well.

 

Sometimes or more often than they should, gear sets get chipped or nicked during the manufacturing process. In most cases they are outside the contact pattern, and they can be removed in a few minutes of careful polishing. It is a best practice to use a medium grit 3M disk to polish out the nick or nicks and scratches inside of the contact pattern. I cannot tell if they are within the contact pattern, however; not finding any debris or chunks in the housing and especially the magnet makes me think that you are good to go as is. The suspect marks on the gears gear may have been there previously and were positioned out of direct sight the last time the fluid was changed. Don't sweat this, just get that pinion seal replaced.

 

And just to be sure that there are no pieces in the old gear oil, take an automotive paint strainer, piece of cheesecloth,etc and filter the old fluid through it. This will assure you that there are no chunks of gear material in it.

 

I appreciate the words, hopefully it isn't serious. I have a buddy who is a service guy in San Antone and he's going to have one of his guys take a look at my photos and get back to me. Can't have too many eyes on it just in case. I guess I'll drive the Charger R/T around until I get the all clear from my buddy <sigh>

I'll plan to get that seal changed out though. Don't need my $60 fluid dripping out on the road.


I won't be able to strain the fluid. I already poured it into the big container. It was very translucent and I watched it drain from the diff as well as when I poured it into the big catch pan. I didn't see anything obvious flow through. It look like of like a waterfall, the kind where the water sticks together in one clear sheet, like on a fabulous vacation.